Split seconds flyback chronograph



m 10, 1951 G. DUBE'Y Em 2,548,101

SPLIT SECONDS FLYBACK CHRONOGRAPH Filed March 4, 1947 2 Sheets-Sheet l NYE/V7035: Georges Dub And Rene Saba/daybrmd ATTflfiA/EY April 10, 1951 a. DUBEY ETAL 2,543,)?l

SPLIT SECONDS FLYBACK CHRONOGRAPH Filed March 4, 1947 2 Sheets-Sheet 2 P/// h M i I"! .6 41 as i 42 XII NVENT0 75 76 my;

76 Saba/denbmnd ri -3g a A TTOFYNEY Patented Apr. 10, 1951 SPLIT SECONDS FLYBACK CHRONOGRAPH Georges Dubey and Ren Schaldenbrand, La Ghaux-dc-Fonds, Switzerland Application March 4, 1947, Serial No. 732,282 In Switzerland March 12, 1946 2 Claims. 1

This invention relates to so called split seconds fly back chronographs, that is to chronographs with two co-axial long seconds-hands, one of which is a fiy-back hand.

An important feature of the invention resides in that the movable elements of the two secondshands are connected with each other by means of a spiral spring and that one of the said seconds-hands carries a stop adapted to engage the other seconds-hands.

Other features and advantages of the invention will appear from the following description. Two practical embodiments of this invention are illustrated in the accompanying drawings, in which:

Fig. l is a top plan view of the chronograph movement of the first embodiment in which only the parts necessary to the understanding of the invention are represented.

Fig. 2 is a partial top plan view of the same movement illustrating the function thereof.

Fig. 3 is an axial sectional view on enlarged scale of the seconds movable elements.

Fig. 4 is a top plan view of the chronograph movement of the second embodiment in which only the parts necessary to the understanding of the invention are represented.

Fig. 5 is a top plan view on reduced scale of this second embodiment, and

Fig. 6 is an axial sectional view on enlarged scale of the seconds movable elements.

With reference to the Figure l in which are represented the principal elements of a usual chronograph minute-register, l designates a center bridge 2, the usual chronograph wheel, 3 the minute-register wheel, 4 the starting lever acting under the control of a pusher (not shown) through the medium of its click 5 on the column wheel 6 the columns of which are indicated 5'. l designates the pawl of the column wheel and 8 an intermediate rocking lever actuated by the column wheel and against which bears one extremity of the chronograph yoke 9 carrying at its other extremity the rocking pinion It which may be driven in usual way by the watch movement. ll designates a friction spring, l2 the minute-register yoke carrying the minute-register rocking pinion I3 and adapted to operate by its nose l2 the locking lever M the projection [4' of which is adapted to lock the setting-to-zero hammer l5. l6 designates the pawl of the minuteregister wheel, I! a brake, and I8 the setting-to-zero sliding lever acting on the minuteregister yoke I2, under the acion of a pusher not shown. The various restoring springs acting on 2 the hereinbefore mentioned elements are designated R to R The chronograph is provided with two coaxial long seconds-hands, namely the usual chronograph or plain seconds-hand l9 secured to the hollow shaft 2!] and the seconds-hand 21, the shaft 22 of which (Fig. 3) passes through the hollow shaft 29 from end to end and is pivoted on the bottom side of the chronograph in a pierced jewel 23 set in an auxiliary bridge 24 which may be designated fly-back bridge, the seconds-hand 2| being a fly-back hand. On the hollow shaft 20 there are secured the chronograph wheel 2 and the heart-shaped cam 25 for setting the seconds-hands to zero. On the back portion of the hollow shaft 20 is further secured a bush 26 to which is attached the inner extremity of a spiral spring 21 the outer extremity of which is attached to a stud 28 screwed in the rim of a wheel 29 which will be designated fiyback Wheel. This fly-back wheel is fixed on the shaft 22 of the fly-back seconds-hand 2!. This latter hand is provided at its extremity with an inwardly bent lug 38 adapted to be urged against the plain chronograph hand [9 under the action of the spiral spring 21. A stopping device of the fry-back movable elements 2I22-29 comprises a stop-arm 3| secured to the intermediate rock ing lever 8 and a push-arm 32 secured to the setting-to-zero sliding lever l8.

The operation of this chronograph is as follows: In the Figure 1 the various members of the chronograph movement are at rest, the chronograph being stopped. To start the chronograph, a pressure is put through the medium of a pusher not shown upon the starting lever 4. Upon pressure of the click 5 of starting lever 4, the column wheel 6 is rotated one step; the column 6' actuates the intermediate rocking lever B which releases the chronograph yoke 9 thus causing the rocking pinion H] to mesh with the chronograph wheel 2 for starting the chronograph minute-register movement. The hollow shaft 20 carrying the plain chronograph hand 19 rotates also the fly-back wheel through the medium of the spiral spring 21 and consequently both the seconds-hands I9 and 2| begin to rotate together as a whole in close engagement with each other by the lug 31]. The rotation of the intermediate rocking lever 8 causes the extremity of the stop-arm 3| to come nearer to the periphery of the fly-back wheel 29; the bend 3| of arm 3| faces the extremity of the push-arm 32; these members occupy the position shown in full lines in Fig. 2.

Pressure upon the setting-to-zero sliding lever 38 in the direction of the arrow 1 causes the pusharm 32 to press the stop-arm 3| against the rim of the fly-back wheel 2;: thus stopping said wheel, its shaft 22 and its seconds-hand 2! against the action of the spiral spring 2'! while the whole plain chronograph movable elements Z !$-2fi including the bush 25 continue to rotate, consequently more and more tensioning the spring 27. The stopping position of the arms 32 and 3! is shown in dotted lines in Fig. 2.

As soon as the pressure on the sliding lever i8 is released, the arms 35, 32 release the flyback wheel 29 which is suddenly swung forward by the spring 2'6 until the fly-back seconds-hand 2i catches up the plain chronograph hand is against which its lug 36 comes to bear again.

A time up to 59 seconds may be readily, measured without stopping either the plain chronograph hand l9 and the minute-register.

The second embodiment of the invention shown in the Figures 4 to 6 is also a split seconds flyback chronograph minute register comprising two co-axial long seconds-hands, namely the plain chronograph hand ll secured to the hollow shaft 42' and the seconds-hand i3 secured to the shaft M passing through the hollow shaft 42 from end to end. Hollow shaft 42 is pivoted on the bottom side of the chronograph in a pierced jewel lfi set into a bridge 46 which may be designated chronograph bridge. On the hollow shaft 42 there are secured the chronograph wheel ll and a setting-to-zero heart-cam Q8. On the sleeve 53'. of the fly-back seconds-hand 33 is fixed a bush 58 to which is attached the inner end of the spiral spring 59, the outer extremity of which is attached to a stud 5| secured to the acorn t! of the plain chronograph hand ll. The point of the fiy-back seconds-hand 33 is provided with an inwardly bent lug 52 pointed towards the dial plate 53 and adapted to be pressed against the chronograph hand t! by the spiral spring as.

The stopping device for the fly-back movable elements comprises on the one hand, a resilient stop arm 5d secured to the frame on the bottom side thereof by two screws 55 and 55 and adapted to frictionally engage by its free end a semi- B0 slidingly mounted within the winding crown 6|; a restoring spring 62 attached to a screw 53 screwed in the chronograph bridge it tends to maintain the lever 58 and the pusher 5B in the inoperative position as shown in the Figures 4 and 6, in which position the lever 58 does not operate the stop-arm 5 thus leaving the latter away from the head 57.

In operation, as the plain chronograph hand il fixed to the hollow shaft 5.2 is running under the action of the chronograph wheel ll driven by the watch movement, the seconds-hand il drives through the medium of the spiral spring 5i} the fly-back hand 33, and both said seconds-hands rotate together as a whole in close engagement with each other by the lug 52. A pressure applied onto the pusher 65 causes the lever 58 to r0 tate against the action of the restoring spring 62 and the inclined surface 58' of its free end to frictionally engage with the semi-spherical head 57 of the shaft it. The fiy-back hand :33 is thus stopped while the chronograph hand 4| continues to rotate consequently more and more tensioning the spiral spring 55. As soon as the pressure upon the pusher Eli is released, the lever 58 is brought back into inoperative position by the restoring spring 52 and the stop-arm 44 is retracted from the head 52', consequently the fly-back seconds-hand 13 is suddenly swung forward under the action of the spiral spring 50 until it catches up the hand 4! against which the lug 52 comes to bear again.

Whatwe claim is:

1. In a split seconds lily-back chronograph, the combination with the chronograph movement of a hollow shaft carrying a first long seconds hand, a bearing for said hollow shaft, situated at its back end, a chronograph wheel secured on said hollow shaft and driven by the movement, a second shaft passing through said first hollow shaft from end to end and carrying a second long seconds-hand, said second shaft having its back end emerging from said first hollow shaft and formed with a semi-spherical head, a spiral spring mounted co-axially with said shafts between said first and second long seconds-hands and connecting them directly, a stop on one of said seconds-hands adapted to nornrially engage the other seconds-hand, and a manually operable device adapted to be brought in axial engagement with said semi-sperical head for displacing axially said second shaft, that brings momentarily said head, in braking engagement with said hearing, thus stopping said second shaft and its long seconds-hand only, in order to measure a time to 59 seconds Without stopping the chronograph movement.

In a split seconds fly-back chronograph, the combination as claimed in claim 1 wherein the braking device comprises a resilient arm, a lever and a pusher, said lever acting, under the action of said pusher, on the free extremity of said resilient arm by means of an inclined surface.

GEORGES DUBEY. RENE SCI-IALDENBRAND.

CITED The following references are of record in the file of this patent:

V UNITED STATES PATENTS Number Name Date 226,195 Wales Sept. 30, 1879 415,577 Lugrin Dec. 31, 1889 1,456,313 Johanson May 22, 1928 1,967,157 Thornton-Norris July 17, 193% 2,058,712 Muir et a1. Oct. 27, 1

FOREIGN PATENTS Number Country Date 185,465 Switzerland Oct. 16, 1936 

